package com.hpf.consumer.lb;

import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * @description:
 * @datetime: 2020/10/1 11:01
 * @author: huangpengfei
 */
@Component
@Slf4j
public class MyLb implements LoadBalance {

    private AtomicInteger atomicInteger = new AtomicInteger(0);

    private final int getAndIncrement(){
        int current = 0;
        int next = 0;
        do {
            current = this.atomicInteger.get();
            next = current >= 2147483647 ? 0 : current + 1;
        }while (!this.atomicInteger.compareAndSet(current,next));
        return next;
    }

    @Override
    public ServiceInstance instances(List<ServiceInstance> instances) {
        int index = getAndIncrement() % instances.size();
        return instances.get(index);
    }
}
